The present invention relates to the field of ocular surgery.
Deprivation of visual stimulus before the age of about eight, due to cataract removal or other causes such as blood in front of the eye, asymmetric need for glasses over one eye due to for example shortsightedness, or any other condition that blocks the center of the visual axis, can lead to a condition called amblyopia (am-blee-oh-pee-ah) or xe2x80x9clazy eyexe2x80x9d. In this situation, the eye itself is intact and has the potential for functioning but the proper brain connection is withered due to the period in which the eye was denied light exposure and visual stimuli and permanent serious impairment of vision can result. For a discussion of this well known condition, reference may be made to U.S. Pat. No. 5,900,921 to Min and U.S. Pat. No. 6,149,615.
Infants after birth can require ocular surgery involving removal of a vision blocking condition such as a cataract in the baby""s eye. The conventional procedure involves replacing the removed natural lens bearing the cataract, with infant configured external eyeglasses or alternatively, with a contact lens so that the infant can focus upon objects and use the xe2x80x9cbadxe2x80x9d eye. The other xe2x80x9cgoodxe2x80x9d eye is covered with an eye patch to force the infant to use the operated on eye in order to prevent amblyopia.
In the common case of cataract removal, a strong lens is positioned over the operated on, now lens-less eye, to enable the infant to focus upon objects and thus maintain visual stimulation to thwart amblyopia, while applying a patch or eye-drops, rendering vision fuzzy, to occlude the good eye and accordingly force the infant to use the operated on eye. Unlike the situation where adults wear glasses to restore vision, certain problems arise when the above mentioned external eyeglasses are supplied for use with an infant, as they are often removed by the infant who is annoyed by them or shifted in position by the infant so that he can peek around the lens. This often results in the use of contact lenses. However, contact lenses are a nuisance to periodically remove and clean to prevent infection in the case of adult usage, and to remove and clean the contact lenses worn by an infant, thrashing about, can be even more aggravating. Injury to the child""s eye is also possible under these circumstances. Hence, a solution to these problems is desired.
In order to more conveniently thwart infant amblyopia, the presently preferred method of the invention includes the steps of providing a flexible visually clear thermoplastic mask-like sheet member having an opaque vision blocking area to be positioned over the infant""s xe2x80x9cgoodxe2x80x9d eye and a large plastic corrective lens to be positioned in place over the infant""s xe2x80x9cbadxe2x80x9d eye under correction. During manufacture of the mask, the large plastic lens can be readily heat laminated to the transparent flexible thermo-plastic mask-like sheet member. The mask can be mounted upon the child""s face in one step since both the large plastic lens and light blocking substitute for the patch are both part of the mask. This is in contrast with applying the external eyeglasses or contact lens in one step and a separate patch in another step.
In accordance with another method of carrying out the invention, a thin annular plastic lens mounting ring is provided, having an upper adhesive surface and a lower adhesive surface. Outer lower peripheral portions of the plastic lens overlap and become affixed to inner rim upper adhesive portions of the annular ring during manufacture of the lens unit. Upon use of the ring unit, the lower adhesive portions of the ring are manually affixed to facial portions of the infant surrounding the eye under correction. A separate strapless adhesive bearing eye patch is concurrently manually applied to cover the good eye to thwart amblyopia. Thus, the large plastic lens
Accordingly, in both embodiments, the plastic lens is larger than the largest eye of most infants subject to treatment, to remove the need for lens size fitting. The large plastic lens directly clings to the infant""s face over the eye to preclude the xe2x80x9cpeek aroundxe2x80x9d tendency of external eyeglasses or precludes the need for inconvenient contact lens insertion and removal.